1
|
Thermally averaged photoassociation controlled by pure cubic pulse. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
2
|
Paliwal P, Deb N, Reich DM, Avoird AVD, Koch CP, Narevicius E. Determining the nature of quantum resonances by probing elastic and reactive scattering in cold collisions. Nat Chem 2020; 13:94-98. [PMID: 33257885 DOI: 10.1038/s41557-020-00578-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 10/14/2020] [Indexed: 11/09/2022]
Abstract
Scattering resonances play a central role in collision processes in physics and chemistry. They help build an intuitive understanding of the collision dynamics due to the spatial localization of the scattering wavefunctions. For resonances that are localized in the reaction region, located at short separation behind the centrifugal barrier, sharp peaks in the reaction rates are the characteristic signature, observed recently with state-of-the-art experiments in low-energy collisions. If, however, the localization occurs outside of the reaction region, mostly the elastic scattering is modified. This may occur due to above-barrier resonances, the quantum analogue of classical orbiting. By probing both elastic and inelastic scattering of metastable helium with deuterium molecules in merged-beam experiments, we differentiate between the nature of quantum resonances-tunnelling resonances versus above-barrier resonances-and corroborate our findings by calculating the corresponding scattering wavefunctions.
Collapse
Affiliation(s)
- Prerna Paliwal
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Nabanita Deb
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel M Reich
- Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, Berlin, Germany
| | - Ad van der Avoird
- Institute of Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Nijmegen, Netherlands
| | - Christiane P Koch
- Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, Berlin, Germany.
| | - Edvardas Narevicius
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
| |
Collapse
|
3
|
Lecomte JM, Kirrander A, Jungen C. Time-dependent resonant scattering: an analytical approach. J Chem Phys 2013; 139:164111. [PMID: 24182008 DOI: 10.1063/1.4825335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A time-dependent description is given of a scattering process involving a single resonance embedded in a set of flat continua. An analytical approach is presented which starts from an incident free particle wave packet and yields the Breit-Wigner cross-section formula at infinite times. We show that at intermediate times the so-called Wigner-Weisskopf approximation is equivalent to a scattering process involving a contact potential. Applications in cold-atom scattering and resonance enhanced desorption of molecules are discussed.
Collapse
Affiliation(s)
- J M Lecomte
- Laboratoire Aimé Cotton du CNRS, Ba^timent 505, Université de Paris-Sud, F-91405 Orsay, France
| | | | | |
Collapse
|
4
|
Tomza M, Skomorowski W, Musiał M, González-Férez R, Koch CP, Moszynski R. Interatomic potentials, electric properties and spectroscopy of the ground and excited states of the Rb2 molecule: ab initio calculations and effect of a non-resonant field*. Mol Phys 2013. [DOI: 10.1080/00268976.2013.793835] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Michał Tomza
- a Faculty of Chemistry , University of Warsaw , Warsaw , Poland
- b Theoretische Physik , Universität Kassel , Kassel , Germany
| | | | - Monika Musiał
- c Institute of Chemistry , University of Silesia , Katowice , Poland
| | - Rosario González-Férez
- d Instituto Carlos I de Física Teórica y Computacional and Departamento de Física Atómica, Molecular y Nuclear , Universidad de Granada , Granada , Spain
| | | | | |
Collapse
|
5
|
Affiliation(s)
- Christiane P. Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Strasse 40,
34132 Kassel, Germany
| | - Moshe Shapiro
- Department
of Chemistry, University of British Columbia, Vancouver, Canada V6T
1Z1, and Department of Chemical Physics, The Weizmann Institute, Rehovot, Israel 76100
| |
Collapse
|
6
|
Beser B, Sovkov VB, Bai J, Ahmed EH, Tsai CC, Xie F, Li L, Ivanov VS, Lyyra AM. Experimental investigation of the [sup 85]Rb[sub 2] a [sup 3]Σ[sub u][sup +] triplet ground state: Multiparameter Morse long range potential analysis. J Chem Phys 2009; 131:094505. [DOI: 10.1063/1.3194290] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
Fukuhara T, Takasu Y, Kumakura M, Takahashi Y. Degenerate Fermi gases of ytterbium. PHYSICAL REVIEW LETTERS 2007; 98:030401. [PMID: 17358662 DOI: 10.1103/physrevlett.98.030401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Indexed: 05/14/2023]
Abstract
Evaporative cooling was performed to cool fermionic 173Yb atoms in a crossed optical dipole trap. The large elastic collision rate leads to efficient evaporation and we have successfully cooled the atoms to 0.37+/-0.06 of the Fermi temperature, that is to say, to a quantum degenerate regime. In this regime, a plunge of evaporation efficiency was observed as a result of Fermi degeneracy.
Collapse
Affiliation(s)
- Takeshi Fukuhara
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | | | | | | |
Collapse
|
8
|
Tojo S, Kitagawa M, Enomoto K, Kato Y, Takasu Y, Kumakura M, Takahashi Y. High-resolution photoassociation spectroscopy of ultracold ytterbium atoms by using the intercombination transition. PHYSICAL REVIEW LETTERS 2006; 96:153201. [PMID: 16712155 DOI: 10.1103/physrevlett.96.153201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Indexed: 05/09/2023]
Abstract
We observed high-resolution photoassociation spectra of laser-cooled ytterbium (Yb) atoms in the spin-forbidden 1S0 - 3P1 intercombination line. The rovibrational levels in the 0u+ state were measured for red detunings of the photoassociation laser ranging from 2.9 MHz to 1.97 GHz with respect to the atomic resonance. The rotational splitting of the vibrational levels near the dissociation limit were fully resolved due to the sub-MHz linewidth of the spectra in contrast to previous measurements using the spin-allowed singlet transition. In addition, from a comparison between the spectra of 174Yb and those of 176Yb, a d-wave shape resonance for 174Yb is strongly suggested.
Collapse
Affiliation(s)
- Satoshi Tojo
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | | | | | | | | | | | | |
Collapse
|
9
|
Przybytek M, Jeziorski B. Bounds for the scattering length of spin-polarized helium from high-accuracy electronic structure calculations. J Chem Phys 2005; 123:134315. [PMID: 16223296 DOI: 10.1063/1.2042453] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We developed a series of correlation-consistent, polarized multiple zeta basis sets optimized specifically for the energy of the 2 3S state of helium atom. These basis sets were subsequently augmented with diffuse functions optimized for the van der Waals constants C6 through C14 which determine the asymptotic behavior of the second-order dispersion interaction between 2 3S helium atoms at large interatomic separation R. The resulting bases were applied to compute the Born-Oppenheimer (BO) potential for the lowest 5Sigmag+ state of the helium dimer. The coupled cluster and the full configuration-interaction techniques were employed to account for the electron correlation effects. The cardinal number extrapolation technique was used to obtain the complete-basis-set limit V(R) for the interaction potential and to find its lower VL(R) and upper VU(R) bounds. The resulting potentials were fitted to an analytical function containing accurate van der Waals constants C6 through C12 (including C11). We found that the complete-basis-set BO potential has a well depth De=1048.24+/-0.36 cm-1. The highest rotationless vibrational level is bound by D14=90.2+/-4.7 MHz, much stronger than the previous most accurate estimation of 15.2 MHz. The error bounds for De and D14 were obtained using the VL(R) and VU(R) potentials. The S-wave scattering length computed using the VL(R), V(R), and VU(R) potentials (assuming atomic masses) is aL=7.41 nm, a=7.54 nm, and aU=7.69 nm, respectively. We also computed the adiabatic, relativistic, and quantum electrodynamics (QED) corrections to the BO potential. When these corrections are taken into account the values of D14 and of a (both computed assuming nuclear masses) are 87.4+/-6.7 MHz and 7.64+/-0.20 nm; the error bounds reflect now also the uncertainty of the included adiabatic, relativistic, and QED corrections. The value of the scattering length resulting from our investigation lies outside the error bounds of all experimental determinations based on the properties of Bose-Einstein condensate of spin-polarized helium atoms.
Collapse
Affiliation(s)
- Michał Przybytek
- Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland
| | | |
Collapse
|
10
|
Wright MJ, Gensemer SD, Vala J, Kosloff R, Gould PL. Control of ultracold collisions with frequency-chirped light. PHYSICAL REVIEW LETTERS 2005; 95:063001. [PMID: 16090943 DOI: 10.1103/physrevlett.95.063001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Indexed: 05/03/2023]
Abstract
We report on ultracold atomic collision experiments utilizing frequency-chirped laser light. A rapid chirp below the atomic resonance results in adiabatic excitation to an attractive molecular potential over a wide range of internuclear separation. This leads to a transient inelastic collision rate which is large compared to that obtained with fixed-frequency excitation. The combination of high efficiency and temporal control demonstrates the benefit of applying the techniques of coherent control to the ultracold domain.
Collapse
Affiliation(s)
- M J Wright
- Department of Physics, U-3046, University of Connecticut, Storrs, Connecticut 06269, USA
| | | | | | | | | |
Collapse
|
11
|
Abstract
The predissociation data for the 1 (1)Pi state of (39)K(85)Rb of Kasahara et al. [J. Chem. Phys. 111, 8857 (1999)] are combined with the recent determination of the long range C(6) coefficients of the predissociating 2 (3)Sigma(+) approximately 2(0(-)), 2(1) states [Wang et al., Eur. Phys. J. D31, 165 (2004) ] molecule: to infer a more precise dissociation energy of the (39)K(85)Rb molecule D(0)=4180.06+/-0.42 cm(-1) and D(e)=4217.91+/-0.42 cm(-1).
Collapse
Affiliation(s)
- William C Stwalley
- Department of Physics, University of Connecticut, Storrs, CT 06269-3046, USA
| |
Collapse
|
12
|
van Kempen EGM, Kokkelmans SJJMF, Heinzen DJ, Verhaar BJ. Interisotope determination of ultracold rubidium interactions from three high-precision experiments. PHYSICAL REVIEW LETTERS 2002; 88:093201. [PMID: 11864003 DOI: 10.1103/physrevlett.88.093201] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2001] [Indexed: 05/23/2023]
Abstract
Combining the measured binding energies of four of the most weakly bound rovibrational levels of the 87Rb2 molecule with results of two other recent high-precision experiments, we obtain exceptionally strong constraints on the atomic interaction parameters in a highly model independent analysis. The comparison of (85)Rb and (87)Rb data, where the two isotopes are related by a mass scaling procedure, plays a crucial role. We predict scattering lengths, clock shifts, and Feshbach resonances with an unprecedented level of accuracy. Two of the Feshbach resonances occur at easily accessible magnetic fields in mixed-spin channels. One is related to a d-wave shape resonance.
Collapse
Affiliation(s)
- E G M van Kempen
- Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | | | | | | |
Collapse
|
13
|
Geltman S, Bambini A. Triplet scattering lengths for rubidium and their role in Bose-Einstein condensation. PHYSICAL REVIEW LETTERS 2001; 86:3276-3279. [PMID: 11327949 DOI: 10.1103/physrevlett.86.3276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2000] [Indexed: 05/23/2023]
Abstract
The triplet scattering lengths of 85Rb and 87Rb are evaluated as a function of C6 using a potential whose short-range form is fitted to an ab initio result. This is combined with a previous analysis of photoassociation measurements, which allows the determination of bounds on C6 and the scattering amplitudes to give sharper bounds for these quantities. Questions are raised about the use of scattering length as the sole atomic parameter in the description of Bose-Einstein condensates.
Collapse
Affiliation(s)
- S Geltman
- JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309-0440, USA
| | | |
Collapse
|
14
|
Sortais Y, Bize S, Nicolas C, Clairon A, Salomon C, Williams C. Cold collision frequency shifts in a 87Rb atomic fountain. PHYSICAL REVIEW LETTERS 2000; 85:3117-3120. [PMID: 11019280 DOI: 10.1103/physrevlett.85.3117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2000] [Indexed: 05/23/2023]
Abstract
We present measurements of cavity frequency pulling and collisional frequency shifts in a 87Rb fountain with a frequency resolution of 3x10(-16). Agreement with theory is found for the cavity pulling and the measured collisional shifts. The clock shift is found at least 50 times smaller than in 133Cs.
Collapse
Affiliation(s)
- Y Sortais
- BNM-LPTF, Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France
| | | | | | | | | | | |
Collapse
|
15
|
Oppel M, Paramonov G. Picosecond laser control of bond-selective dissociation and clockwise and anticlockwise rotation of the dissociation fragments: applications to a three-dimensional model of HONO2 in the ground electronic state. Chem Phys 1999. [DOI: 10.1016/s0301-0104(99)00319-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
16
|
Stwalley WC, Wang H. Photoassociation of Ultracold Atoms: A New Spectroscopic Technique. JOURNAL OF MOLECULAR SPECTROSCOPY 1999; 195:194-228. [PMID: 10329265 DOI: 10.1006/jmsp.1999.7838] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The new spectroscopic technique of photoassociation of ultracold atoms is reviewed, with an emphasis on connecting this area to traditional bound-state molecular spectroscopy. In particular, in contrast to photoassociative spectra at thermal energies, which are broad and of low information content, photoassociative spectra of ultracold atoms are high resolution, permitting observation of small vibrational and rotational spacings of long-range molecular levels near dissociation (typically with outer classical turning points >20 Å). The types of detection and theoretical analysis employed are illustrated, primarily using the example of 39K2. Future directions and applications of this field (e.g., to ultracold molecular formation) are also discussed. Copyright 1999 Academic Press.
Collapse
Affiliation(s)
- WC Stwalley
- Department of Physics, University of Connecticut, 2152 Hillside Road, Storrs, Connecticut, 06269-3046
| | | |
Collapse
|
17
|
Korolkov M, Schmidt B. Vibrationally state-selective laser pulse control of electronic branching in OH (X/A) photoassociation. Chem Phys 1998. [DOI: 10.1016/s0301-0104(98)00219-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
18
|
Backhaus P, Manz J, Schmidt B. Effect of Rotations and Shape Resonances on Photoassociation and Photoacceleration by Short Infrared Laser Pulses. J Phys Chem A 1998. [DOI: 10.1021/jp9800057] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Backhaus
- Institut für Physikalische und Theoretische Chemie, WE 3, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
| | - J. Manz
- Institut für Physikalische und Theoretische Chemie, WE 3, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
| | - B. Schmidt
- Institut für Physikalische und Theoretische Chemie, WE 3, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
| |
Collapse
|